Deviously enter election with a Democrat breaking this international agreement (7,8)
I believe the answer is:
entente cordiale
'this international agreement' is the definition.
'entente cordiale' can be an answer for 'agreement' (entente cordiale is a kind of agreement). I am unsure of the 'this international' bit.
'deviously enter election with a democrat breaking' is the wordplay.
'deviously' indicates an anagram (I've seen this in other clues).
'with' means one lot of letters go next to another.
'democrat' becomes 'd'.
'breaking' means one lot of letters goes inside another.
'enter'+'election'+'a'='enterelectiona'
'enterelectiona' with letters rearranged gives 'ententecoriale'.
'ententecoriale' going around 'd' is 'ENTENTE CORDIALE'.
Can you help me to learn more?
(Other definitions for entente cordiale that I've seen before include "Understanding" , "Agreement" .)